New data released by the Maccabi Healthcare Services has confirmed the effectiveness of the Pfizer coronavirus vaccine.
As of Thursday, only 254 individuals out of the 416,900 who were already a week after the second Pfizer shot – the time where the immunity is considered to kick in – got infected with the virus, the organization reported. Moreover, those who were found to be positive only had light symptoms, with just four of them being hospitalized, all of them in light condition.
Over the same period of time, some 12,944 new cases of COVID-19 emerged in the control group of some 778,000 people having a diverse health profile.
A comparison between the data from the two groups shows that the vaccine is 91% effective seven days or more after the second injection is administered.
From a segmentation of the infections that did occur, it appears that the immunity increases as the days go by. Among the 254 people who contracted the virus, 76 of them were infected after seven days, 44 on the eight day, and 24 on the ninth day. Between day 22 and 24 – when the test period ended – no one was infected.
According to the studies conducted by Pfizer, the vaccine had an efficacy of about 95%, which is considered very high.
With some 2.5 million members, Maccabi is the second largest health fund in Israel. About 900,000 of its customers have already received the first shot, and about 500,000 the second one.
“The data continue to be very encouraging and to show that the effectiveness of the vaccine is high and stable,” Dr. Anat Aka Zohar, head of Maccabi’s Information and Digital Health Division said. “The findings clearly indicate that as the days go by after the second dose, the immunity becomes stronger.”
She also emphasized that the vaccine does not only protect against infection but also again developing more severe symptoms.
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COVID: Just 0.06% Israelis sick after two shots, no one serious – study. According to a Maccabi Healthcare study, immunity appears to further strengthen even after seven days from the second injection.
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2021-2-5 英国研究人员发现，单一剂量的阿斯利康疫苗除了可使接种疫苗的人群免疫外，还可有效降低新冠病毒传播率达七成以上
2021-2-5 英国研究人员发现，单一剂量的阿斯利康疫苗除了可使接种疫苗的人群免疫外，还可有效降低新冠病毒传播率达七成以上。
一份最新研究指出，单剂阿斯利康疫苗就可对接种疫苗者形成有效保护，不仅能防止感染新冠病毒，还能减少病毒传播。
一般情况下，接种疫苗后，虽然接种者本身能获得抗体免于感染，但仍可能将病毒传播给他人。但牛津大学的最新研究发现，注射第一剂阿斯利康疫苗后可以阻断三分之二的病毒感染。此外，虽然单剂疫苗无法形成完整保护，但疫苗似乎能防止接受接种者出现重症。
有效降低病毒传播率
研究人员表示，一剂阿斯利康疫苗在接种超过两个月后，疫苗的有效性仍维持在76%。研究指出，在接种疫苗的22天到12周后，这种保护“没有太多减弱的迹象”。
一名阿斯利康制药公司高管表示，没有任何病患在接受第一剂疫苗注射的三周后出现严重病症或住院，疫苗的效力在初次注射的12周内有所提高。
阿斯利康生物制药研究和开发执行副总裁潘加洛斯（Mene Pangalos）称：“我们的数据显示，（接种第二剂疫苗的）时间越接近这12周越好。”
这份研究尚未经过同行评估。但研究得出的结果为英国及部分国家推迟施打第二剂疫苗，以便让更多人注射第一剂疫苗的策略提供了理论基础。
研究报告写道，推迟施打第二剂疫苗的接种时间表，“对于短期内供应量有限的流行病疫苗的推出而言，可能是最佳做法”。
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Pfizer, Moderna, AstraZeneca and Novavax: How COVID-19 vaccines are made 2021-2-4
More than 100 million people across 66 countries have received at least one COVID-19 jab, and all in just a few short months.
Not only were these vaccines developed and tested at blistering pace — less than a year — but they’re also being produced on a mass scale.
So how are they made?
Some production details are trade secrets.
But we do know that the three vaccine technologies we’re likely to get in Australia don’t incorporate, or even handle, the actual virus that causes COVID-19.
They instead use genetic instructions for a very specific part of the SARS-CoV-2 virus, the spike protein, which the virus uses to hook onto and infect our cells.
And while they all grow (or culture) cells and microbes in bioreactors as part of their production, they all do it differently.
Growing spike protein antigens
The most conventional style of vaccine is the protein subunit vaccine. The Novavax jab, as well as most of the jabs we get in childhood, fall under this umbrella.
These vaccines stimulate an immune response by directly delivering bits of the virus they’re designed to protect us against.
There are a few ways to make these bits, called antigens, but they all generally involve cell lines: populations of cells living in a soup of nutrients and other essential compounds.
A commonly used cell line in mass antigen production are Chinese hamster ovary or CHO cells, which are pretty hardy little things: they can put up with swings in temperature, pH and oxygen levels.
The cells can also make and churn out loads of a specific molecule, such as the SARS-CoV-2 spike protein, if given the genetic instructions to do so.
(No hamsters were harmed in the making of the vaccine. This cell line and others used in vaccine production were descendants from cells isolated from an animal years, perhaps even decades, ago.)
CSIRO’s Melbourne biologics production facility scaled up the spike protein antigens used in the University of Queensland’s vaccine clinical trials last year, says Susie Nilsson, Biology Group Leader at CSIRO Biomedical Manufacturing and a lab head at the Australia Regenerative Medicine Institute.
Bioreactors are standard cell culture equipment. Lab-based bioreactors can be only a few litres in volume, wihle large-scale ones can hold more than 10,000 litres. The engineered CHO cells are grown inside bioreactors. Batches of cells are bagged separately to avoid contamination.
“And if you do it right, you get the antigen secreted from the cells right into the soup,” Professor Nilsson says.
Novavax production forgoes CHO cells; rather, it employs cell lines extracted from moths to manufacture its spike protein antigens.
The moth cells get their instructions to generate antigens from a virus that only infects insects.
mRNA wrapped in a greasy sheath
The newest style of vaccine are mRNA vaccines, such as those developed by Pfizer/BioNTech and Moderna.
These are fairly basic in structure, with just a strand of genetic material — that’s the mRNA or messenger RNA — encapsulated in a protective envelope.
The message carried by the mRNA is a blueprint for our cells to construct copies of the SARS-CoV-2 spike protein, which we then use to train our immune system to recognise in case it sees the real thing down the track.
To make these vaccines, you first need a DNA template to make the mRNA, says Magdalena Plebanski, a professor of immunology at RMIT University.
“You can synthesise DNA fully artificially, but it’s a real pain,” she says.
“So if you want a large amount, you can incorporate it into an organism where it grows, and then you harvest it.
“It’s the quickest, cheapest and easiest way of doing it.”
Once you have your DNA templates, they’re incubated in a cocktail of mRNA building blocks and enzymes.
The enzymes follow the template to construct mRNA strands.
Because mRNA strands tend to fall apart easily, they need to be protected in a fat-rich sheath called a lipid monoparticle.
To safely ensconce the mRNA in its protective monoparticle, they’re shot at each other in a process called impingement jet mixing.
“Everything swirls around in the jet mixer and they create nanoparticles,” Professor Plebanski says.
Genes housed in a virus
The Oxford/AstraZeneca and Johnson & Johnson vaccines use a different type of virus, an adenovirus, to protect us against SARS-CoV-2.
These adenoviruses don’t make us sick, but contain the genetic blueprint for the SARS-CoV-2 spike protein.
But unlike mRNA vaccines, where the instructions are in the form of a long, fragile single-stranded molecule, genetic instructions in adenovirus vaccines form part of a ring of double-stranded DNA.
This makes them much more stable than mRNA vaccines, and is why they can be stored at normal fridge temperatures.
It almost sounds counterintuitive to deliberately use a virus in a vaccine.
But scientists can harness a virus’s ability to efficiently deliver genes into cells, while removing parts of its genome to ensure it can’t replicate in a vaccinated person’s cells.
Instead, it carries the spike protein DNA instructions into the cell, where the genes are “read” and transcribed into mRNA.
From there, it’s the same process as the mRNA vaccines.
The DNA in the vaccine does not get incorporated into your own DNA, either. After a time, the DNA ring is dismantled and destroyed by the cell’s natural waste disposal processes.
And making adenovirus-based vaccines is relatively straightforward once you have a sample of the vaccine, Professor Plebanksi says.
The process also uses cells living and growing in bioreactors, but instead of CHO cells, adenovirus vaccine production enlists the help of a particular cell line dubbed HEK 293.
Even though HEK 293 cells originally came from a human — a kidney, back in 1973 — they are engineered to allow vaccine adenoviruses to replicate inside them.
“So you take a sample of your adenovirus vaccine, you infect your cells, and you let them grow,” Professor Plebanski says.
Purifying and packaging
At various stages of the production process, vaccines and their components must be filtered.
This not only ensures the product is pure, but also sterile.
First, they spin the solution to get rid of the chunks, namely the cells in which the vaccine components grow.
The remaining liquid is then usually sent trickling through special membranes or resin columns in a process called chromatography, which separates components from the soup.
Then it’s simply a matter of collecting the pure product from the resin or membranes.
Before packaging, vaccines are mixed with a buffer solution — often saline — and sometimes other compounds such as adjuvants, which help “wake up” your immune system and elicit a stronger response.
They’re then packaged into vials and shipped off to where they’re needed. But this is a whole other story.
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I’m a doctor and one of my best friends doesn’t believe in vaccines. This is what I want to tell her 2021-2-4
It’s a sunny morning here in the Austrian Alps. There is half a metre of snow in our garden, with one half-finished igloo in the middle of it, abandoned by my three kids when the temperature hit minus-10.
There’s a cup of English Breakfast tea and a piece of Vegemite toast beside me. And my left upper arm is, I’ll admit it, a little bit sore. Why? I thought you’d never ask…
Thanks to my job as a doctor in a small regional hospital in Tirol, yesterday I received the Pfizer COVID vaccine. And although you might think that I resent the residual muscle ache (just a normal post-vaccination tenderness, no other symptoms), I actually kind of love it. My fingers keep finding it and pressing it, like a kid with a bruise.
Because it reminds me of what it means.
It means that my body’s cells are ingesting the genetic material (called mRNA) from the vaccine, decoding it and making the COVID spike proteins on their surfaces.
It means that my body’s immune system is, as I type these very words, encountering those spike proteins for the first time, recognising them as foreign intruders, and mounting an attack on them.
It means my body is actively creating custom-made antibodies which will stick to the spike proteins and help disable and eliminate those infected cells.
And best of all, it means any future invasions of real virus particles won’t stand a chance, because my body will remember those spike proteins from the vaccination and — like flicking a switch — simply pump out floods of the same antibodies it made last time, resulting in a coordinated and speedy attack.
Science is just so bloody cool.
Vaccinating isn’t a personal decision
One of my best friends here in Austria is a musician with four kids. She is one of the kindest souls I know.
She also doesn’t believe in vaccination. For the sake of social harmony, we always avoid the topic when it arises (we are both big believers in the general principle, “live and let live”).
However, I want to say to her that when her husband has sudden-onset chest pain, it’s me who she brings him to in the emergency department. It’s me and my medical knowledge she is putting her trust in when she asks me to find out what’s wrong and treat him. So why doesn’t she trust that same medical knowledge when he’s healthy?
I want to tell her that I love her soul. That she is more patient and kind than I could ever be. But that her anti-vax views are contradicting that entirely. Because to not vaccinate is not just a personal decision: it’s a big F-YOU to all the people in your community.
Sure, you might not care about getting measles or the flu or COVID (even though you should; have I told you about the otherwise very fit and healthy 46-year-old from my ward, who has been on the ICU with COVID since November and is currently awaiting a lung transplant if he doesn’t die first?).
But you’re right, chances are that if you’re healthy, and get COVID, you will barely feel it. Hold up, though — your argument also applies to getting a vaccine: you are healthy, so in all likelihood you will barely feel it.
The problem is that we humans are suckers for the status quo. When life is good, we’re hardwired to coast along, and not do anything to disrupt that. It’s only when shit (like our health) hits the fan, that we suddenly desperately want someone to DO SOMETHING, ANYTHING, to make it better again.
Look to history — and the future
So why get the vaccine when we’re all pictures of health? Let me count the reasons.
Even though I may not know all of the ins and outs of this particular vaccine, or the big-business pressures and deals undoubtedly going on behind closed doors, I know that there is a well-established and rigorous independent regulatory system in place to make sure the experts are held accountable and deliver a safe and effective product.
History has shown us, time and time again, that vaccines are the single most effective way to stop pandemics. Have you ever wondered why anti-vaxxers are rarely over the age of 70? Because most of our grandparents remember the devastation of infectious diseases like polio and how massively vaccination helped.
Selfishly, I don’t want to get as sick as the man trying to outpace death waiting a set of new lungs. And because I don’t want my grandparents to either, by me inadvertently giving the virus to them.
On purely practical level, I want our lives to return to normal. We are on our third hard lockdown here (the 23rd week of home schooling since last March) and I can tell you, the days I work on the COVID ward are a holiday compared to home schooling two primary schoolers with a toddler in tow. I want restaurants and hotels and shops to open up and make jobs again.
I want to fly back to Australia and see my family.
Above all, I will do it because of 6-year-old Sophie. She’s on the leukaemia ward, locked up in there for months with only her mum to visit. She is still waiting on chemotherapy that hasn’t been able to be administered due to COVID delays.
I don’t know Sophie personally — I’ve only heard about her through my colleagues on that ward — but I don’t want to be the type of person who ignores her just because I don’t know her. There are thousands of Sophies.
So yep. Even though my arm is admittedly a little bit sore today, I will be getting my booster in three weeks. And even though I hate doctors’ waiting rooms, and even though my toddler (and probably his older sisters too) will definitely scream at the jab in the arm, it’s way more important to me to put Sophie’s needs before my own kids’ comfort.
That’s just the kind of person I want to be.
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什么是新冠病毒居家检测包
总部位于布里斯班的生物技术公司Ellume刚刚与美国签订了一份价值3.02亿澳元的合同，以提高新冠病毒居家检测工具包的产量。
根据合约，美国国防部将从Ellume公司处购买850万个居家检测工具包，并将在全美各地分发。
由于美国新冠病例数激增，并且确实需要大量能够快速得出结果的居家检测产品，因此这家总部位于布里斯班西南部里奇兰兹（Richlands）的公司将重心放在美国市场。
下文提供了一些关于这种居家检测工具包的信息。
测试如何进行？
工具包中附有关于自己进行拭子检测的说明，其侵入性远低于目前大多新冠检测诊所使用的深层鼻咽拭子（被人们戏称为“Brain tickler，大脑挠痒棒”）。
除此之外，工具包中还有一个分析器（analyser），通过蓝牙与智能手机相连，并使用一个免费的应用程序即可在15分钟内获得检测结果。
如果所做的抹拭不正确，则会有详细的指南告知使用者，而且在下载应用程序之后，该程序就会指导用户完成抹拭。
Ellume公司称，公司已经经过了严格的测试，以确保结果是可靠的。
为什么这么快即可获得结果？
居家测试的过程可能极其简单，但解读其背后用到的技术却要复杂得多。
用Ellume公司首席执行官肖恩·帕森斯博士（Sean Parsons）的话说:
“分析器内置了一个特殊的薄膜，用于输送流体。
“一种基于量子点的荧光纳米粒子被创造出来，如果存在病毒，它就会发出信号。
“它与一种叫做核半胱氨酸蛋白的病毒蛋白结合，仪器可以通过荧光方法检测出这种蛋白，公司在研发这种方法上花了大量的时间和金钱。
“所有的处理都由安装在分析器上的微芯片来完成。”
谁将受益？
居家测试对新冠病毒高感染风险人群特别有用，如老年人和任何患有呼吸系统疾病的人士。
对于任何行动不便的人或没法离开家的人也是一个很好的选择。
任何希望避免在检测诊所排长队的人也可能会使用居家测试的办法。